Apparatus for the manufacture of helically coiled pipes of thin sheet metal

ABSTRACT

AN APPARATUS FOR THE MANUFACTURE OF CORRUGATED, HELICALLY COILED AND WOUND PIPES OF THIN SHEET METAL OR METAL FOIL INCLUDES A MULTI-ROLL MACHINE IN WHICH A STRIP OF SHEET METAL IS CORRUGATED AND A COILING MACHINE IN WHICH THE CORRUGATED STRIP IS COILED HELICALLY INTO A PIPE. THE MULTI-ROLL MACHINE HAS CORRUGATED ROLL PAIRS WHICH ARE PROVIDED WITH CORRUGATING GROOVES WHICH PROGRESSIVELY AND GRADUALLY NARROW AND DEEPEN IN THE DIRECTION OF TRAVEL OF THE STRIP THROUGH THE MACHINE SO THAT THE STRIP DURING THE FORMATION OF CORRUGATIONS IS DEFORMED ONLY BY BENDING AND DOES NOT UNDERGO COMPRESSION OR STRETCHING. THE COILING MACHINE IS PROVIDED WITH ENTRY GUIDE ROLLS WHICH PREPARE THE EDGES OF THE CORRUGATED STRIP BY SLIGHTLY BENDING THE EDGE CORRUGATIONS WITHOUT COMPRESSION OR STRETCHING DEFORMATION. THUS WHILE THE CORRUGATED STRIP IS BEING COILED ON A COILING MANDREL OF THE COILING MACHINE, THE DOWNWARDLY OPEN CORRUGATION AT THE EDGE OF THE UPPERMOST CONVOLUTION OF THE STRIP ENGAGES IN THE UPWARDLY OPEN CORRUGATION OF THE ADJACENT LOWERMOST CONVOLUTION OF THE STRIP. THESE INTERENGAGING CORRUGATIONS ARE HELD TOGETHER BY COMPRESSION BY ROLLS ON THE COILING MACHINE ACTING AGAINST THE MANDREL TO FORM A JOINT. THE JOINT IS SUBJECTED TO PRESSURE BY AN ADDITIONAL ROLL LOCATED BEYOND THE MANDREL IN THE DIRECTION OF MOVEMENT OF THE STRIP TO LOCK THE CORRUGATIONS SECURELY TOGETHER.

M81611 1971 L. WESTERBARKEY 3, 3

APPARATUS FOR THE MAN CTURE 0F HELICALLY COILED PIPES OF N SHEET METAL Filed April 9, 1969 V 7 SheetsSheet 1 lnrenfor: L. Nesterbarue Filed April 9, 1969 March 1971 L. WESTERBARKEY 3, 66,

APPARATUS FOR THE MANUFACTURE OF HELICALLY COILED PIPES 0F THIN SHEET METAL 7 Sheets-Sheet 2 March 2, 1971 L. WESTERBARKEY 3,566,643

APPARATUS FOR THE MANUFACTURE OF HELICALLY COILED PIPES OF THIN SHEET METAL Filed April 9, 1969 7 Sheets-Sheet 3 Fly- I I /II a.

lnremar- L, westerbara B25 @JMj-fiRLfi-f TTTTT N535 Mardl 1971 WESTERBARKEY 3,566,643

APPARATUSFUR THE MANUFACTURE OF HELICALLY COlLI'Jl) PIPES OF THIN SHEET METAL Filed April 9, 1969 7 Sheets-Sheet 4 lnremor: L. h/esferbarxqg A QRMEa March 1971 WESTERBARKEY 3,565,643

APPARATUS FOR THE MANUFACTURE OF EELIcALLY COILED PIPES OF THIN SHEET METAL Filed April 9. 1969 7 Sheets-Sheet 8 In wen/0r:

L, lA/estarbccrmejl mmlw ATTOILNISBS March 2, 1971 L. WESTERBARKEY 3,566,643

APPARATUS FOR THE MANUFACTURE OF HELICALLY COILED March 2, 1971 L. WESTERBARKEY 3,566,643

APPARATUS FOR THE MANUFACTURE OF HELICALLY COILED PIPES OF THIN SHEET METAL Filed April 9, 1969 TStxeets-Sheet 1 Alllllllllllillllllllllll R l lnrenfor- L. Hester ban-Ka s wake-(J's 731110" United States Patent 01 ifice 3,566,643 Patented Mar. 2, 1971 3,566,643 APPARATUS FOR THE MANUFACTURE OF HELICALLY COILED PIPES F THIN SHEET METAL Lorenz Westerbarkey, Zum Stillen Frieden, Guetersloh, Germany Continuation-impart of application Ser. No. 573,110, Aug. 17, 1966. This application Apr. 9, 1969, Ser. No. 814,695

Int. Cl. B21c 37/12 US. Cl. 72-49 11 Claims ABSTRACT OF THE DISCLOSURE An apparatus for the manufacture of corrugated, helically coiled and wound pipes of thin sheet metal or metal foil includes a multi-roll machine in which a strip of sheet metal is corrugated and a coiling machine in which the corrugated strip is coiled helically into a pipe. The multirol1 machine has corrugated roll pairs which are provided with corrugating grooves which progressively and gradually narrow and deepen in the direction of travel of the strip through the machine so that the strip during the formation of corrugations is deformed only by bending and does not undergo compression or stretching. The coiling machine is provided with entry guide rolls which prepare the edges of the corrugated strip by slightly bending the edge corrugations without compression or stretching deformation. Thus while the corrugated strip is being coiled on a coiling mandrel of the coiling machine, the downwardly open corrugation at the edge of the uppermost convolution of the strip engages in the upwardly open corrugation of the adjacent lowermost convolution of the strip. These interengaging corrugations are held together by compression by rolls on the coiling machine acting against the mandrel to form a joint. The joint is subjected to pressure by an additional roll located beyond the mandrel in the direction of movement of the strip to lock the corrugations securely together.

This invention relates to an apparatus for the manufacture of corrugated, helically coiled and wound pipes of thin sheet metal and metal foil.

The present application is a continuation-in-part of the copending patent application filed Aug. 17, 1966, Ser. No. 573,110, now abandoned.

Pipes of the type to which the invention relates are mainly used in heating, ventilating and air-conditioning systems. Corrugated and helically-coiled pipes already known in the art are composed of several layers of paper or plastics film combined with metal foil. The individual layers are bonded together. When pipes of this type are partly composed of paper, they have the disadvantage of being sensitive to humidity and in certain conditions may not possess the desired degree of resistance at high temperatures or when there is risk of fire.

The present invention is a development of apparatus for the manufacture of corrugated and helically-coiled pipe from thin sheet metal or metal foil, in which a multi-roll machine, which feeds a strip uncoiled from a spool between a large number of mutually-opposed roll pairs with corrugating members of increasing depth, so that the strip is provided with corrugations extending parallel to strip edges, the corrugations being approximately sinusoidal in cross section, the corrugated strip then being taken to a coiling machine which forms it by twisting by guide rollers that are inclined with respect to a rotating mandrel, into a helically-wound pipe.

An object of the present invention is to improve the pipe manufacturing apparatus of this type.

Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found advisable to provide an apparatus for the manufacture of corrugated and helically-coiled pipes from thin sheet metal or metal foil, having a multiroll machine in which a strip of sheet metal is corrugated, and a coiling machine in which the corrugated strip is coiled helically into a pipe, wheren the corrugating roll pairs of said multi-roll machine are provided with corrugating grooves that progressively and gradually narrow and deepen in the direction of travel of the strip through the machine, so that said strip, during the formation of the corrugations, is deformed only by bending and does not undergo compression or stretching, and wherein the coiling machine is provided with entry guide rolls which prepare the edges of the corrugated strip by slightly bending the edge corrugations without compression or stretching deformation, so that while the corrugated strip is being coiled on a coiling mandrel of the coiling machine, the downwardly open corrugation at the edge of the uppermost convolution of the strip engages in the upwardly open corrugation of the adjacent lowermost convolution of the strip, said interengaging corrugations being held together by compression by rolls on said rolling machine acting against said mandrel to form a joint, said joint being further subjected to pressure by an additional roll located beyond said mandrel in the direction of movement of said strip, securely to lock said corrugations together.

The surface of the first pair of rolls on the multi-roll machine is provided with grooves of approximately sinusoidal cross section. The surfaces of the remaining pairs of rolls on the machine are provided with spaced ribs of rectangular cross section. These rectangular-section ribs are advantageously rounded on their outer surfaces. The entry guide rolls of the coil machine advantageously consist of two roll pairs of which the first pair preliminarily open the opposed grooves on the edges of the strip and bend them approximately at right angles, and the second roll pair engage in the second groove from the edge and bend the first groove steeply. The first roll at least on the coiling machine overlaps the compressed fold of the strip on the mandrel, joins it together and compresses it. If desired, several or all the rolls on the coiling machine effect this overlapping, joining and compressing operation. An outer and inner folding roller are arranged on the end of the mandrel and compress the fold. These folding rollers are provided with a milled edge which may be exchangeable and have a counteropposed pattern. The milled edge may also take the form of printed indicia or characters or symbols. One, preferably the outer one, of the folding rollers is driven from flexible shaft and in addition effects the withdrawal of the coiled pipe from the mandrel.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings, showing, by way of example only, a preferred embodiment of the inventive idea.

In the drawings:

FIG. 1 is a side view of a complete assembly of apparatus according to the invention;

FIG. 2 is a schematic perspective view of the coiling machine, several parts thereof having being omitted for simplification of the drawing;

FIGS. 3a to 32 show various roller sections of the multiroller machine, the rolls having progressively varying profiles;

FIGS. 4a and 4b show further embodiments of corrugating tools;

FIG. 5 is a plan view, partly cut away, of the coiling machine;

FIG. 6 is a view of the first pair of entry guide rolls in the coiling machine;

FIG. 7 is a view of the second pair of entry guide rollers in the coiling machine;

FIG. 8 is a development of the coiling machine in one plane;

FIG. 9 shows the position of the corrugated strip when being applied to the mandrel of the coiling machine;

FIG. 10 shows the position of the strip coiled on the mandrel;

FIG. 11 is a section through the folding rolls;

FIG. 12a is a view of the surface of the folding rolls; and

FIG. 12!] is a side view of the folding rolls in the coiled position.

So far as the construction of the strip from thin sheet metal and the forming tools are shown in the drawing, these are shown on an exaggerated scale in order to make the proportions clearer to see.

Referring now to the drawings, FIG. 1 shows the whole assembly of apparatus. In this figure a support 1 carries a spool 2 of thin sheet metal or metal foil so that the latter can rotate. The metal strip 3 is taken from this spool into a machine 4 which comprises a large number of roll pairs schematically indicated as 5a to 52, through which the strip is passed. One roll of each pair is provided with a gear wheel 6 on the same shaft, and this may be the upper and lower roll alternately, as shown. These gear wheels 6 engage each other and at least one of these gears is driven by a suitable drive (not shown), if desired through a gear box.

The roll pairs 5 of the machine 4 are provided with grooves which gradually narrow and deepen progressively in the direction of the strip feed. Some of the successive roll pairs of the machine are shown in cross section in FIG. 3 and for illustrative purposes the cross sections of the pair 5a correspond to the section shown in FIG. 3a; the pair 5b corresponds to that of FIG. 3b; the pair 50 corresponds to that of FIG. 3c; the pair 5d corresponds to that of FIG. 3d and the pair 5e corresponds to that of FIG. 3e. The roll pairs lying between these numbered pairs have appropriate sections to form a sequential transition and progressive variation between the selectively illustrated sections.

Reference to the various sections shown in FIG. 3, will make it apparent that when the sheet material 3 is passed through the first roll pair 5a having the section 3a, it will be corrugated with an approximately sinusoidal deformation. The width of the sheet metal after forming, is less than the original width of the incoming sheet metal, the disposition of the rolls ensuring that the sheet metal is not stressed in any way either by compression or stretching as the corrugations are formed therein, but only bent or deformed in shape. Thus, the strain on all parts of the strip is the same. It is to prevent weakening that the final desired shape of the corrugations is not made in a single step or only a few steps and the grooves and intermediate ribs that comprise the forming tools only gradually but progressively narrow and deepen during passage through the machine 4 to create progressively deeper corrugations. With the roll section shown in FIG. 3b the strip is more deeply corrugated, actually by ribs 7 between the grooves in the rolls. The ribs 7 project from one roll towards the other and are mutually imbricated. The ribs 7 apply pressure to the internal face of the bend of the corrugation so that the sinusoidal shape produced by the first roll pair 5a with the section shown in FIG. 3a is narrowed and deepened. The distance between the individual ribs 7 of the roll pair of FIG. 3 is less than the apex distance of the individual sinusoidal shapes of the roll pair section according to FIG. 3a. These conditions also apply to the following roll pair sections according to FIGS. 3c, 3d and 3e. The greater the degree of projection of the ribs 7 from their respective rolls, the less the distance between the individual ribs. The ratio of the projection of the ribs from the rolls to the distance between them is so selected, that nei ther a compression nor a stretching of the sheet metal can occur during the deformation. Stressing of the material is also prevented or minimized by ensuring that the ribs only engage from below into the previously made shaping of the corrugations in the sheet metal. From the representations of FIGS. 3a to 3e it is apparent that the sheet metal strip between the ribs is completely free and thus will also bend freely. Also due to this special construction of the corrugating tools formed by the profiled rolls, compression or straining of the sheet metal strip is prevented. The sheet metal strip is thus able to shift freely with respect to the flanks of the inner ribs so that it is deformed only by bending. As will be clear from the representations of FIGS. 3a to 3e, as the strip travels through the roll pairs it becomes overall progressively narrower as the corrugations become narrower and deeper so that when it leaves the final roll pair 5e it has approximately only half the overall width of the original strip on entry between the first roll pair 5a.

In order to facilitate the deformation of the strip and further to decrease any imposed strain, the apices of the ribs 7 can be rounded, as shown in FIGS. 3b and 4a. In FIG. 4a another construction is shown of the grooved and ribbed corrugation roll tool. With these tools, somewhat wider grooves are produced which, for example, are formed by the last pair of rollers according to FIG. 4b in such a way that they have an approxi mately trapezoidal cross section with widths as great as possible on the upper and lower apices. A pipe produced from material corrugated in this manner has relatively smooth outer and inner surfaces but is, however, not quite so flexible or bendable as a pipe with a larger number of narrower corrugations.

The sheet metal strip 3 corrugated as described above is fed from the multi-roll machine 4 into a coiling machine 8 (FIG. 1), in which the strip is firstly conveyed straight and accurately between the entry guide rollers 9 and 10 so that it lies on the underside of the rotating coiling mandrel 11. In addition to conveying the sheet metal strip, the rolls 9 and 10 must also prepare the edges of the sheet metal strip for the folding operation hereinabove referred to. For this purpose, as shown in FIG. 6, the roll pair 9 is constructed in such a way that the edges of the sheet metal strip project substantially at right angles from the general or median transverse plane of the sheet metal strip. This is actually a safety precaution. From FIG. 3e it can be seen that the edges are not quite at right angles to said transverse plane of the strip. It is possible for the corrugation strip to be ternporarily rolled up before being fed to the coiling machine to be formed into the shape of a pipe. If such a rolled strip is transported, it is possible for the edges thereof to be damaged by bending in several places. The shaping of the rollers section as in FIG. 3e minimizes such damage.

After the strip edges have been bent by the first entry roll pair 9 as shown in FIG. 6, at right angles to the meridian transverse plane of the strip, the strip is then fed to the second roll pair '10 as shown in FIG. 7. The ramps 12 of the roll pair 10 engage into the second groove from each edge of the strip and bend it back somewhat outwardly so that the outer edge corrugation becomes inclined. This form is clearly visible in FIG. 7.

The thus prepared strip now runs onto the coiling mandrel 11 of the coiling machine 8. A constant rotation is imparted to the coiling mandrel 11 by means of a drive not shown in the drawings. In FIG. 9, the position is shown in which the first convolution of the strip 3 is fed onto the coiling mandrel 11 so that it extends helically therearound and the next convolution 3a is applied to the mandrel Ill. Thereby, the upwardly bent edge of the convolution 3a engages from below in up wardly and outwardly bent edges of the convolution 3b already coiled on the coiling mandrel 11 and is pressed thereon by the first coiling roll 12 (FIG. 10). The first coiling roll 12 which cooperates with the coiling mandrel 11, overlaps the convolution 3a coiled on the mandrel 11 and is provided at the center with a shaped portion 13 (FIG. which engages, in the edges of both the convolutions prepared for folding and lying above one another, and compresses them together. Then both convolutions already coiled on the mandrel 11 are positively fed through by the ribs of the coiling roll 12 which engage in the corrugations of the convolution throughout the whole width thereof, so that in bending the edges together so as to prepare the fold no shifting of the convolutions on the coiling mandrel can occur. The further coiling rolls 14, which are arranged helically around the periphery of the coiling mandrel 11 likewise overlap two convolutions of the strip 3 adjacent to one another; they can be provided above the folding between both the edges of the strip with further folding pressure tools but they may alternatively leave this area free.

The strip 3 coiled on the coiling mandrel 11 into a pipe or liner whose individual convolutions are connected together, by folding their coadjacent edges, is fed, after leaving the mandrel ends 15, to a pair of folding rolls 16'. The position of this roll is fixed, and the inner roll, which lies within the pipe emerging from the coiling mandrel 11, is carried by a fixed arm so that it can rotate, while the outer roller is rotatively arranged, like the coiling rollers, on another fixed arm (FIG. 2). The folding rollers are likewise provided with individual ribs on their surfaces, which engage in the corrugations of the corrugated pipe running from the coiling mandrel 11, on both sides of the fold, so as to be guided as is best shown in #FIG. 11, from which it can be seen that folded sections 17 and 18 lie between these guide ribs. Thus there are flat parts on the folding rolls 16. The flat part 17 of the inner roller is backwardly located with respect to the ribs and lies approximately on the surface of the roll. The fiat part 18 of the outer roller 16 projects slightly and lies roughly at the level of the ends of the ribs of the other roll. The compressed fold is pressed together between these flat parts 17 and :18, so that both the parts lie close to one another rigidly and securely.

The flat parts 17 and 18 of the folding rolls are advantageously provided with a milled edge so that there is additionally a coining of the fold. This milled edge consists, in accordance with FIG. 12b, which shows a cross section thereof, of small projecting ribs which can be mutually oppositely staggered. These ribs can be arranged at right angles to the side boundary of the flat parts 17 and 18 of the folding roll, as is shown to the left of FIG. 12a; they may alternately be provided with a pattern of lines that change direction, for example, a herringbone pattern, which is shown to the right of FIG. 12a. Another possible pattern for the milled edge is in the form of indicia such as written characters or symbols. The pattern could, for example, form letters of the alphabet to make wording projecting from the flat parts 17 and 18 of the folding roll. One of the folding rolls 16 can be driven. If the outer folding roll is driven this can be eifected by means of a flexible shaft. Thereby the effect is additionally achieved of withdrawing the pipe formed on the coiling mandrel from this latter.

Pipes or liners produced by the apparatus according to the invention may be bent acutely so that the diameter of the curve around which the bend takes place, is approximately equal to the diameter of the pipe itself. In other words, the total diameter between the outer walls at the bend is approximately equal to three pipe diameters.

I claim:

1. An apparatus for manufacturing corrugated and helically coiled pipes from a strip of sheet metal or metal foil, said apparatus comprising, in combination, a multiroll machine having a plurality of corrugating roll pairs for corrugating a metal strip moving consecutively between the rolls, said roll pairs having corrugating grooves which progressively and gradually narrow and deepen in the direction of movement of the strip, whereby the strip is deformed only by bending and does not undergo compression or stretching, and a coiling machine for coiling the corrugated strip helically into a pipe, said coiling machine comprising entry guide rolls receiving the corru gated strip from said multi-roll machine and slightly bending the edge corrugations thereof without compres sion or stretching deformation, a coiling mandrel receiving the strip from the entry guide rolls and winding it, whereby the downwardly open corrugation at the edge of the uppermost convolution of the strip engages in the upwardly open corrugation of the adjacent lowermost con volution of the strip, other rolls pressing against said mandrel and holding together said interengaging corrugations to form a joint, and an additional folding roller located beyond said mandrel and pressing against said strip after it leaves said mandrel for securely locking said corrugations together.

2. Apparatus in accordance with claim 1, wherein the first one of said roll pairs has corrugating grooves of substantially sinusoidal cross section.

3. Apparatus in accordance with claim 2, when the other roll pairs have spaced ribs of rectangular cross section.

4. Apparatus in accordance with claim 3, wherein said rectangular ribs are rounded on their outer surfaces.

5. Apparatus in accordance with claim 1, wherein said entry guide rolls on said coiling machine consist of two pairs of rolls, whereby the first pair preliminarily opens the opposed grooves on the edges of the strip and bends them approximately at right angles, and the second roll pair engages in the second groove from the edge and bends the first groove steeply.

6. Apparatus in accordance with claim 5, wherein at least the first of said other rolls of the coiling machine overlaps the compressed fold of the strip on the mandrel, joins it together and compresses it.

7. Apparatus in accordance with claim 6, comprising an additional folding roller, said two folding rollers being aftrganged on the end of said mandrel and compressing the 8. Apparatus in accordance with claim 7, wherein said folding rollers are provided with a milled edge.

9. Apparatus in accordance with claim 8, wherein the milled edge of said folding rollers is provided with a pattern of lines that change direction.

10. Apparatus in accordance with claim 8, wherein said milled edge is in the form of indicia.

11. Apparatus in accordance with claim 8, comprising a flexible shaft driving one of said folding rollers, whereby the withdrawal of the coiled pipe from the mandrel is effected.

References Cited UNITED STATES PATENTS 3,132,616 5/1964 Hale et al. 72-49 3,247,692 4/1966 Davis 72-49 3,263,321 8/1966 Lombardi 72-49X MILTON S. MEHR, Primary Examiner US. Cl. X.R. 7218O 

